Question

我创建了以下表格：

/sdcard -> /storage/self/primary
cd /storage/self
ls -la
primary -> /mnt/user/0/primary
cd /mnt/user/0/

我插入了以下数据：

create table people (
        ID              varchar(9),
        name            varchar(20),
        CONSTRAINT pk_ID PRIMARY KEY (ID)
);

 create table cars (
        license_plate   varchar(9),
        ID              varchar(9),
        CONSTRAINT pk_ID PRIMARY KEY (license_plate)
);

create table accidents (
        code          varchar(9),
        license_plate varchar(9),    
        CONSTRAINT pk_ID PRIMARY KEY (code)
);

问题是：如何选择在任何车辆上没有发生事故的人？

我的问题是，当我尝试使用insert into people(ID, name) values('0x1','Louis'); insert into people(ID, name) values('0x2','Alice'); insert into people(ID, name) values('0x3','Peter'); insert into cars(license_plate, ID) values('001','0x1'); insert into cars(license_plate, ID) values('002','0x2'); insert into cars(license_plate, ID) values('003','0x1'); insert into cars(license_plate, ID) values('004','0x3'); insert into accidents(code, license_plate) values('fd1','001'); insert into accidents(code, license_plate) values('fd2','004'); insert into accidents(code, license_plate) values('fd3','002');时。拥有＆＃34; Louis＆＃34;表not in中至少有一辆车，查询显示我＆＃34;路易斯＆＃34;并且不应该显示＆＃34;路易斯＆＃34;。

我的查询：

accidents

结果：

select ID from people where ID in (select ID from cars where license_plate not in (select license_plate from accidents));

Answer 1

select name from people where ID not in (
  select distinct c.ID from 
    accidents as a inner join cars as c 
    on a.license_plate = c.license_plate 
)

说明=子查询将加入汽车和事故，将为您提供所有发生事故的汽车的ID。在此，您可以在人员表

上运行not in查询

Answer 2

我需要两个子查询

        select id from people 
        where id not it 
           (select id form cars where licens_plate not in 
                 (select distintc license_plate  from accidents))

Answer 3

这应该非常快：

SELECT people.* FROM people
LEFT JOIN cars ON cars.ID = people.ID
LEFT JOIN accidents ON accidents.license_plate = cars.license_plate
WHERE accidents.code IS NULL
GROUP BY people.ID

如何在MYSQL中获取身份证？

3 个答案: